1. Field of Invention
The present invention relates to the field of light-emitting diode (LED) lighting, and specifically to an integrated LED module.
2. Description of Related Arts
At present, light sources for street lighting include an incandescent lamp, a high pressure mercury lamp, a high pressure sodium lamp, a metal halide lamp, a fluorescent lamp, and the like. These street lamps generally have the following disadvantages: they are less environmentally friendly (mercury, lead, arsenic and other heavy metals contained therein are harmful to the environment), have high energy consumption and a short service life. Therefore, with the enhancement of global environmental protection consciousness, in countries throughout the world, especially in developed countries and regions, environmentally friendly lighting is more widely applied, and an environmentally-friendly light source will gradually substitute for these street lamps. An LED module with a 3-5V forward voltage is an environmentally friendly light source that has high efficiency, saves energy, and has a long luminescence lifetime, which is of great significance to environmental protection, energy saving, and protection of human health.
As known in the industry, adjustment of the brightness of the LED module with a 3-5V forward voltage is implemented by adjusting a current flowing through an LED, and therefore a brightness control for the LED is usually implemented by controlling an output current of an LED drive circuit. At present, in the field of LED drivers with a 3-5V forward voltage, products vary in quality. In order to reduce a cost, some products are provided with a simple line, have a power factor merely reaching about 0.5, and incur low luminous efficiency, thereby failing to meet a demand for efficient and energy-saving products in market; and in order to meet a high performance requirement, some products have a very complicated circuit. Refer to FIG. 1, which is a schematic diagram of a principle of a drive circuit of a conventional LED module with a 3-5V forward voltage. As shown in FIG. 1, a conventional LED drive power supply includes an electromagnetic interference (EMI) unit 121, an analog/digital (A/D) conversion unit 122, an input and output isolation unit 123, a constant-voltage and constant-current output and overvoltage and overcurrent (an open circuit and a short circuit) protection unit 124, and a power factor correction (PFC) power supply 125, and the like. Because a large number of restrictive devices such as electrolytic capacitors and inductors are used in the above drive circuit, a line is rather complicated, it is difficult to lay a simple line, and the cost is greatly increased; furthermore, specific circuits of different products are also different and it is also highly difficult to develop a circuit, which increases development time; and because a part of the line of the drive power supply is complicated, a manufactured LED lamp is relatively large in size, which seriously affects an overall design of a lamp product and application flexibility thereof.
In the current LED lighting schemes, in order to drive an LED module to emit light, it is necessary to add a drive circuit, to generate an appropriate drive current. When the LED module continuously emits light, it may produce a lot of heat, and it is necessary to add a heat sink to make the LED module not overheat. However, in the current general lamp structure, an LED module, a drive circuit part, and a heat sink of the lamp are independent of each other. Refer to FIG. 2, which is a schematic structural exploded view of a conventional LED lamp. As shown in FIG. 2, the LED lamp structure consists of an LED module 10, a heat sink 11 disposed on the back of the LED module 10 and used for dissipating heat from the LED module 10, a power supply housing 12 for receiving a drive power supply, a light-transmitting shade 13 covering an out-light surface of the LED module, a lid body 14 for sealing the power supply housing, a suspension member 15 connected to the lid body, and the like. As stated above, as a part of the line of the drive power supply of the LED lamp is complicated, components of the LED lamp have to be packaged and integrated by using a large-size power supply housing 12, and due to separate structures of the components, a waste of material costs is incurred, and the LED lamp presented after assembly has a large size and is heavy, which is unconductive to construction of the lamps connected thereto, also prolongs processing and assembling time, and results in a waste of production costs.